idx: Optional Property Traversal Utility

idx is a utility function designed for safely traversing deeply nested properties within JavaScript objects and arrays, where intermediate properties might be `null` or `undefined`. It provides a concise syntax for accessing values without throwing errors. The current stable version is 3.0.3. However, the `idx` package is officially deprecated and no longer maintained. Its primary use case has been superseded by the native JavaScript optional chaining operator (`?.`), introduced in ES2020. A key differentiator noted in its documentation is that `idx` returns the `null` or `undefined` intermediate value if encountered, whereas optional chaining resolves to `undefined`. This library also strictly requires a Babel plugin (`babel-plugin-idx`) for correct transformation and optimal performance, as the runtime function is illustrative and not meant for direct execution. The library does not follow a regular release cadence due to its deprecated status.